The art of additive manufacturing, also known as “3-D printing.” has in recent times advanced dramatically such that 3-D printers are now widely available for use by hobbyist manufacturers. As the availability of such machines has increased, however, so too has the desire of the home manufacturer to produce his or her own plastic filament for use in the machine. To do so, the home user will typically obtain plastic material from any available source, such as, for example, recycled plastic products. The obtained plastic material is then chopped, ground, sliced or otherwise formed into small plastic chips, whereafter the plastic chips are fed into a heated extrusion mold adapted to form the plastic into plastic filament sized for use in the additive manufacturing device.
Unfortunately, this simple sounding process is fraught with difficulty owing in large part to the lack of manufacturing control generally implemented in the hobbyist environment. Of particular issue is the fact that the raw plastic material obtained by the hobbyist will often comprise a mixture of plastics and, in many cases, will be of a composition that is not fully known to the hobbyist. As a result, it is extraordinarily difficult for the hobbyist to establish and maintain the proper mold temperature for producing plastic filament of quality acceptable for use in the 3-D printer. To be sure, the only method available to the hobbyist beyond initial assessment of the raw plastic material for setting a likely melting temperature is for the hobbyist to examine the extrudate emanating from the mold and then making temperature adjustments based on perceived quality.
While to foregoing method is the state of the art, Applicant has found it less than satisfactory. In particular, it is noted that the foregoing method only allows adjustment to be made after the source plastic material has fully traversed the mold, resulting in wasted time and to material. Additionally, and especially to the extent that it is to be expected that the hobbyist obtained raw plastic material will be an inconsistent mixture of plastic types and sizes, the foregoing method required painstaking attention, and often difficult to achieve skill, to continuously monitor the extrudate and make necessary temperature adjustments.
Given these serious shortcomings of the prior art, it is an overriding object of the present invention to improve generally over the prior art by providing a system and method for control of a plastic filament extruder that includes an intrinsic means for indicating to the user that a temperature adjustment is necessary.
Additionally, it is an object of the present invention to provide such a system and method for control of a plastic filament extruder that may also be implemented in an autonomous or semi-autonomous mode.
Still further, it is an object of the present invention to provide such a system and method for control of a plastic filament extruder that is readily adaptable to, or capable of integration with, otherwise conventionally available home extruders.
Finally, it is an object of the present invention to provide such a system and method for control of a plastic filament extruder that is relatively simple and inexpensive to implement, thereby ensuring that the improvements of the present invention are widely available to hobbyist manufacturers.